So will many speakers IMO. There really isn't anything special about the old KEF drivers. It was a very well executed crossover however. I give you the electrical response below. I take it you have studied the "15 ohm" crossover. The notch around 1kHz is significant.
Without the notch, you might end up with something like the Epos ELS-3.
Epos ELS-3 loudspeaker | Stereophile.com
A 5" 4 ohm polycone bass with a metal tweeter. Good drivers IMO, but a simpler crossover which stops short of a notch. I'd expect a good sound, nevertheless. Are we getting the idea now? 😀
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The Harbeth plots show a strong voltage drive below 100Hz and a gradual slope down to 700Hz.
Is this a "baffle step correction"?
Is this a "baffle step correction"?
Yup. Half of the low frequency bass disappears round the back of the cabinet. And there isn't much in the first place with a 5" driver, so you boost it with a big bass coil. You end up with a lump around 100Hz, which doesn't sound too bad, but definitely says "Small Speaker"! 😀
The crossover is a bit of a pig to decipher, but the special feature is the 1khz midrange notch and the Zobel on the tweeter. You can model it if you allow for the steeper rolloff of polycones:
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I took a similar approach with a Visaton W130S 5" paper bass and a TW70 cone tweeter:
An externally hosted image should be here but it was not working when we last tested it.
Looks good on paper. I see this LS3/5A as a STYLE of small speaker. The details are up to you. 🙂
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Harking back to an earlier part of the conversation, note that the strong correction around 800 is mostly required due to the driver rear mounting.
Also note that the two networks are not supposed to match. They are designed so that the final response with subtly different driver sets do match.
David
Also note that the two networks are not supposed to match. They are designed so that the final response with subtly different driver sets do match.
David
Isn't the Daline about three feet high? If so, I might just as well stick with the B J Webb Transmission Line which also uses my B139 🙂
To be honest I am really looking for a smaller design.
Truth is surv1v0r, small speakers have lumpy and lousy bass.
There's no replacement for displacement. By which I mean big boxes and big drivers at the bass end. 🙂
Reflex seems to help the bottom end too. But even so...
I've been working on my Auntie's speakers this afternoon. Below. She won't put up with big speakers, so I compromise at 10L closed box and 6" bass. Not bad at all. 6" is a hard speaker to do, IMO. Needs a notch around 5kHz. Phase to die for though. 😎
As an aside, Lynn Olson's Ariel is an interesting approach to 5" polycone Vifa P13 driver. It has the bass. MTM.
Ariel Speaker Page
For all that, Lynn will admit to blowing a few bass drivers with this speaker. It really can't go loud.
There's no replacement for displacement. By which I mean big boxes and big drivers at the bass end. 🙂
Reflex seems to help the bottom end too. But even so...
I've been working on my Auntie's speakers this afternoon. Below. She won't put up with big speakers, so I compromise at 10L closed box and 6" bass. Not bad at all. 6" is a hard speaker to do, IMO. Needs a notch around 5kHz. Phase to die for though. 😎
As an aside, Lynn Olson's Ariel is an interesting approach to 5" polycone Vifa P13 driver. It has the bass. MTM.
Ariel Speaker Page
For all that, Lynn will admit to blowing a few bass drivers with this speaker. It really can't go loud.
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I fear that you have summed it up pretty well - small speakers lack bass and large speakers get in the way.
I think I'll stick to my large speakers continuing to get in the way 😉
Thanks to all for the discussion - a wee bit of which I can claim to have understood - THANKS.
Could someone who understands the difference between the various BBC LS3/5a crossovers please explain to me in layman's terms what the effective auditory difference is at the human ear? I have tried to understand the description on the Falcon Acoustics site (LINK) but it hasn't entirely helped.
Thanks 🙂
Thanks 🙂
Details of the Daline here
http://www.tech-diy.com/Loudspeakers/Daline/Daline.pdf
Quite shallow and designed to be used against a wall.
For the OP : yes with more bass and in the second hand market ! the name is Kef 104/2 ref.
< 1000 USD / 800 euros / 700 pounds
< 1000 USD / 800 euros / 700 pounds
+1 the Continuum is really an homage to the LS3/5A with modern drivers and modeling techniques applied.
http://www.salksound.com/continuum%20-%20specifications-pricing.htm
Thanks Colin, I had actually considered the Daline some time ago and unfortunately still feel compelled to dismiss it on the grounds of its height (34½"). I have no doubt that it would otherwise be a better use of a pair of B110s & T27s than in LS3/5a clones.
That will be the speaker that uses 2 x B200, 2 x B110 & 1 and a T33 per speaker will it then? Hardly relevant to me - at ANY price.
To put this query into context, I have a pair of four foot high DIY speakers based on the KefKit 3 + Coles 4001G supertweeters. I originally planned to build these into HFA 75 Transmission Line cabinets but am facing some opposition to the idea of spending some £300 on marginally more acceptable (in a domestic sense) cabinets. To compound my problems I carelessly acquired another pair of very tatty three foot high DIY speakers based on the KefKit 3 - it is the B110s & T27 from these that I am now hoping to rehouse in something small and perfectly formed.
If I were starting from scratch I would almost certainly join Colin's group buy plan and build a pair of Jordan Eikona VTLs.
The Jordan VTL design for the JX92 and Eikona is similar in principle to the Daline. Ted developed the idea independently in one of his 1971 Wireless World articles. The VTL is shorter and not as deep.
I take it you're after a bookshelf or stand mount design for your KEF combo? If I had those drivers the design which would attract me (after the Daline) is a HiFi News design called the Miniline. It was published in the late 70s or early 80s and used a B110 and Isophon tweeter. I imagine it would work fine with your pair. It was around 45 cms high and intended for small room monitoring, using a transmission line for extended bass. the overall layout is a bit like a Daline folded into a smaller, deeper enclosure.
It's impossible to find online but I have a PDF scan of the original article. If you are interested, send me a PM.
I take it you're after a bookshelf or stand mount design for your KEF combo? If I had those drivers the design which would attract me (after the Daline) is a HiFi News design called the Miniline. It was published in the late 70s or early 80s and used a B110 and Isophon tweeter. I imagine it would work fine with your pair. It was around 45 cms high and intended for small room monitoring, using a transmission line for extended bass. the overall layout is a bit like a Daline folded into a smaller, deeper enclosure.
It's impossible to find online but I have a PDF scan of the original article. If you are interested, send me a PM.
In response to the original question; in the 70s(?) I can remember reading a joint review of many speakers where the original Kef Coda (7litres, wide shallow cabinet) scored higher than the Ls3/5a.
The LS3/5A style of speaker designer could learn a thing or two from ex-BBC engineer Morgan Jones' masterclass here:
http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html
Using diffraction control to voice a speaker is extremely clever, and easier to implement than a notch filter around 1kHz. Thank you Morgan. 🙂
I'll leave the details as an exercise for the keen student.
http://www.diyaudio.com/forums/diyaudio-com-articles/158899-arpeggio-loudspeaker.html
Using diffraction control to voice a speaker is extremely clever, and easier to implement than a notch filter around 1kHz. Thank you Morgan. 🙂
I'll leave the details as an exercise for the keen student.
This comment reminded me that the B J Webb TL design places the B110 in a Transmission Line measuring about 10" deep by 10" high by 11½" wide with a slot measuring 1½" by 8" - might be worth a look.
Could one offset the B110 to one side and place the T27 beside it?
The T27 is 4¼" in diameter & the B110 is 5½" in diameter (total = 9¾"). I can't think of any other way of fitting them into a box 11½" wide.
Can one build a better (non) Ls3/5a speaker based on T27s and B110s
The original Kef Coda had those drive units, hence my mentioning of it. It also had a very simple crossover!
(not sure why the previous pot went prematurely)
The original Kef Coda had those drive units, hence my mentioning of it. It also had a very simple crossover!
(not sure why the previous pot went prematurely)